koi synth · vst3 · au · standalone

K01

Baby, this ain't a toy, it's a koi.

A straight to the point synth that creates patches itself. Click the koi and it sets every oscillator, operator, filter and envelope.

Clicking the koi (or water) splashes back a new patch.

One click sets the oscillators, the filter, both envelopes, the FM graph and the effects.

You can still tweak the sounds to your liking, and you can save or load any custom patches you create.

The patches K01 creates are based off of hand-selected synth patches I've made over the years, so they start somewhere musical and studio-ready. No AI model generates them, and nothing leaves your computer.

An emphasis on musical, not sound effects.

K01's patches aim to be something you can use in a song, rather than SFX and alien noises. Even if it's a bit off the mark, you're rarely more than a click away from something worth using.

Every patch is rendered offline before you hear it. K01 checks the patch and refines it, up to six times. Designed to prevent overly harsh patches and large jumps in volume.

Full spec
Formats
macOS 11+ (Apple Silicon & Intel): VST3, Audio Unit & Standalone · Windows 10+ 64-bit: VST3 only
Voices
12, or 24 stacked · mono with last-note priority · glide in poly and mono · equal-power pan spread per note
Oscillators
Band-limited sine→saw→PWM carrier morph with a square sub · free-running phases · per-note and per-operator drift
FM
4 operators · 6 fixed algorithms · harmonic ratios only · Tomisawa-averaged feedback · index key-scaled above middle C · operators fade out near Nyquist
Filter
Per-voice 4-pole ladder, 24 dB/oct · lowpass & highpass · one soft tanh inside the resonance loop · 303-style feedback tap
Quality
2× oversampling and first-order ADAA on the shaper, doing different jobs · 16–23 dB together
Envelopes
Two analog-curved ADSRs
Movement
Per-voice vibrato on independent slow clocks, ±4.5% rate spread · Juno-style PWM on its own detuned clock · No assignable LFO
Effects
Chorus · flanger · tempo-syncable modulated echo · SWIRL, an 8-stage phaser
Arpeggiator
7 modes · 12 divisions · 1–4 octaves
Expression
Full MPE — pressure opens the filter, CC74 tilts brightness ±0.6 oct · velocity · mod wheel
Interface
15 knobs reaching 24 parameters via label-click view flips (this is how you access things like filter env and other alt functions) · five-octave keyboard · host-resizable
Automation
Every control the knobs touch, your DAW can too · presets save and load
License
Offline License key. Activate once, no account, no subscription. No internet required
Is this AI?

No, K01 does not use AI to do anything. K01 creates patches by referencing hand-selected patches, performs some magic, measures it, and adjusts it until it sits right. All of that happens on your own machine.

License and activation

A key arrives by email. Paste it in once and click ACTIVATE. Offline activation.

GET K01 →